Hi everyone. Long time lurker, but just registered so I can post. 
I am well aware of the value prop of an insert or even a stove installed into my "regular" masonry fireplace. But, I'm an Engineer and a thinker, so I just have to know about weird ways to do things. haha
I have learned about secondary burn as well as catalytic burns for higher burn efficiency / lower exhaust particulates. I got to thinking about if secondary air injection into a fireplace is possible for a secondary burn. I find a TON of info on air injection at the fire, but almost nothing about a secondary burn above the fire in a traditional fireplace. (I believe that getting all the exhaust gasses to pass through a cat would be nearly impossible, so not really thinking about that, but if you have ideas....)
The only thing that I can find even mentioning secondary burn is the Priorfire, but that doesn't really appear to be "secondary," more like a "more complete first burn."
Again, this is more of a learning, idea sharing, technical exploration kind of topic. Not a "how would I do this in real life" kind of thing. It's likely cost prohibitive compared to the ROI of an insert / stove.
I look forward to the discussion and hearing everyone's thoughts on this thought exercise!
Matthew
Wisconsin

I am well aware of the value prop of an insert or even a stove installed into my "regular" masonry fireplace. But, I'm an Engineer and a thinker, so I just have to know about weird ways to do things. haha
I have learned about secondary burn as well as catalytic burns for higher burn efficiency / lower exhaust particulates. I got to thinking about if secondary air injection into a fireplace is possible for a secondary burn. I find a TON of info on air injection at the fire, but almost nothing about a secondary burn above the fire in a traditional fireplace. (I believe that getting all the exhaust gasses to pass through a cat would be nearly impossible, so not really thinking about that, but if you have ideas....)
The only thing that I can find even mentioning secondary burn is the Priorfire, but that doesn't really appear to be "secondary," more like a "more complete first burn."
Again, this is more of a learning, idea sharing, technical exploration kind of topic. Not a "how would I do this in real life" kind of thing. It's likely cost prohibitive compared to the ROI of an insert / stove.
I look forward to the discussion and hearing everyone's thoughts on this thought exercise!
Matthew
Wisconsin